67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio
Wurz, P.; Bochsler, P.; Altwegg, K.; Balsiger, H.; Berthelier, J. J.; Rème, H.; Bieler, A.; Calmonte, U.; Fiethe, B.; Gasc, S.; Gombosi, T. I.; Rubin, M.; Tzou, C. -Y.; Mall, U.; Korth, A.; De Keyser, J.; Owen, T.; Sémon, T.; Mousis, O.; Marty, B.; Combi, M.; Hässig, M.; Bar-Nun, A.; Briois, C.; Eberhardt, P.; Hansen, K. C.; Jäckel, A.; Kopp, E.; Neefs, E.; Fuselier, S.; Waite, H.; LeRoy, L.
Switzerland, Israel, France, United States, Belgium, Germany
Abstract
The provenance of water and organic compounds on Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the deuterium-to-hydrogen (D/H) ratios in the reservoirs for comets and Earth’s oceans. Here, we report the direct in situ measurement of the D/H ratio in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard the European Space Agency’s Rosetta spacecraft, which is found to be (5.3 ± 0.7) × 10-4—that is, approximately three times the terrestrial value. Previous cometary measurements and our new finding suggest a wide range of D/H ratios in the water within Jupiter family objects and preclude the idea that this reservoir is solely composed of Earth ocean-like water.